Short-distance data links used for consumer electronics are reaching increasingly higher data rates, especially those used for video and data storage applications. Examples include the USB 3.0 protocol at 5 Gb/s, HDMI at 10 Gb/s and Thunderbolt at 10 Gb/s over two channels. At such high data rates, traditional copper cables have limited transmission distance and cable flexibility. For at least these reasons, optical fiber is emerging as an alternative to copper wire for accommodating the high data rates for the next generations of consumer electronics.
Unlike telecommunication applications that employ expensive, high-power edge-emitting lasers along with modulators, short-distance optical fiber links are based on low-cost, low-power, directly modulated light sources such as vertical-cavity surface-emitting lasers (VCSELs). To be viable for consumer electronics, the fiber optic interface modules and assemblies used to couple light from the light source into an optical fiber in one direction and light traveling in another optical fiber onto the photodiode in the other direction need to be low-cost. This requirement drives the need for the design of fiber optic interface modules and assemblies to be simple to manufacture while having suitable performance. Thus, there is an unresolved need for fiber optic interface modules having forgiving misalignment tolerances and a passive alignment process.